Breech mechanism for automatic firearms.



' A. D. GHRONIS. BRBBGH MEGHANISM FOR AUTOMATIC FIREARMS.

APPIIOATIQB `I ILED NOV. 28, 1911.

Patented May 12,- 1914m 3 SHEETS-SHEET 1 4A. D. C gRoNIS.

BRBEGHMEGANISM. FORAUTOMATLG PIREARMS.

APPLIQATION FILED NOV. 28. 1911.

,Patenteamay 1:3., 1914.

@c MTNESSES MMT ' All D. CHRONIS. BRBBGH MBGANISM PoR AUTOMATIC HRMRMSl A APPLICATION FILBDNOV. 28, 1911.

' Panama May 12, Y1914. V

lill/J l s SHEETS-SHEET MESSES f4 f6/@WM i" .lill

' sienne; nenn onine,

ARIS D. CHRONS, OF LARISSA, GREECE, ASSIGNGR T0 THE FIRM OFiRHEINISCI-IE lll/ET.ALTAAAR/EIN' UND VIASCHNENFABRIK, OF DUSSELDORF-DERENDORF, GER- MANY.

renonce.

BREECH MECHANISM FOR AUTOMATIC FIREA'BMS` Patented May 12, 15H4..

Application filed November 28. 1911. Serial No. 662,865.

To all Awhom il: 'muy/concern Be it known that I, Anis D. Cnnoxis, lieutenant, a subject oi the King ci Greece, residing :it Larissa, Greece, have invented certain new and useful Inipmvexnents in Breech hechanisni oritutoinatic Firearms; and I do hereby declare thefollowing to be full, clear, and exact description of the invention, such as will enable others skilled in the art to which it apperteins to make and use the saine.

The invention relates to autoinatil Firearms with Xed barrel and locked breech block, in which the indochine,` is effected by the recoil of the whole weapon as set `forth in niy Patent No. 1,043,670, und the object is to reduce to a minimum the efiort rc quired for unlocking the block.

The advantages of the device consist n: the fact that the mass of the displaceaible member con be considerably reduced and also the unlocking can be effected in weapons in which the recoil yis not suilicientto bring about the automatic action. The locking is positive and is not due to friction, which would cause nn immediate shifting of the cartridge cese on firing due to gas pressure.

The invcrtion is illustrated by way of .exemple in the accornninying drawings.

Figure l is a longitudinal section,tnr(n1gh a weapon provided with a locked breech.'

block at the moment of firing. Fig'. 2 is the saine view after firing', when lhe breech if; unlocked und has reached its most rearward position.y Fig". il is u horizontal longitudinal section after firing when the breech block is unlocked. Fig. 4tis the same section at the moment` of firing, corresponding to the condition shown in Fig'. l. Figs. 5, 6, 7 S are cross sections on the lines 5 5, 6-6, 7-7 and 8-8 of Figs. l, Q, 3 and 4. Figs. 9 and 10 are front, side auditeur views of the fore and rear parts of the breech block.A Fie". ll shows two views of the firing pin. Fig. l2 shows three views of one of the locking bolts. Fig. 13 is a diagraminntic representation of the forcesl acting on lhe bolts.

The breech block consists ol two relatively movable parts, u fore part e (Figs. 1, 2, 3, 4 and 9) and a reur port c (Figs. 1, 2, 3, 4 und l0). The closing spring g is situated in the after part c (Figs. l and 2).

The fore part of the breech bleek (L (Fig. 5)) provided with un internul space i to receive the locking bolts'c (Figs. l, 2, 2l, 4, 5, o. and which can turiion the pins- /1v (Figs. 2l und l) on the fore purl rz. of the block. ln both bolts there ure 'recesses f] with inclined surfaces y, 72 (Figs. 3, el and l2).- l`he tiring' pin mi engages in these recessel o, und is connected with the rear purt o of the breech block by the pin n (Figs. l, 2, 3 and 'The connection between the two parts a and f.' of the breech block-is such that the parts can he pushed one into the other after the firing pin m and the locking bolts e ere inserted in the fore part 1, and the firing pin m connected to the after part through pin nl All these parts are then held in their places. .ifhen the rear part c of the breech block moves to the rear, the locking bolts c are drawn together by the engagement between the inclined surfaces q2 thereof and the correspondingly inclined surfaces m2 of the fir-ing pin m and are forced apart, when vthe rear part c of the breech block is moved forward again by a spring f (Figs. 1, 2, 3, 4;, 5, G).

The action is as `follows: lVhen the breech block is closed the. parts :ire in the positions shown in Figs. l and 4, that is, the two parts o, und c of the breech blockl are maintained in contact by the closing spring g and the locking; bolts c lare held inV breech lockingy position by the spring f andthe firing pin m. lVhen the weapon is red, the backward impulse on the hreechblock, due to the powder gases, is exerted on the fore part a of the hrecchblm-lc and transmitted to the pins it, :1nd by the engagement ofthe locking bolts e thisy force is transmitted to the inclined surface h of the ranle. This force D,-indicatcd in Fig. 13, in which l represents a pin f and 2 the machine surface tf,-gives risc to a reaction B, which can be yresolved intotwo components P. B2, of

which B is at right angles to the surface 7L und B2 is tangential to the surface, and draws the bolts e inward. B2 will depend upon the inclination-of the surface L., that is, upon the angle f( between the direction of the iiorce 'B and the normal to the sur- 'liuee l. rlhe force of the recoil is thus in the seine way in my Patent No.

consequence` of the shape of the locking surfaces iz. and the action caused thereby, the

. element c has only a part -o theunlocking work to perform and can consequently be less massive than in my before mentioned patent;

The angle fl can be so determined, that B2 9fqual to the force required for overcoming itsiiiction or equal to the eoi't necessary for unlocln'ng. The invention causes the work necessary for the unlocking of the weapon bythe movable member c to be reduced to thelowest limit and the member c can be held with less force, since the effort lrequired for unlocking is diminished. Y

In Weapons in which the gas pressure produced on firing quickly disappears, for instance with pistols and the like in which the initial velocity is very high, so that a premature unlocking is not likely to occur,`the angle 'r can be made so-great that the force B2 can be not only as' great as the. force necessary for unlocking, but somewhat greater, so that the unlocking can be effected without the assistance of .any displaceable member. With ythis assum tion the breech block can consist of a sing e piece.- If the unlocking is completed before the weapon comes to rest, that is beforethe recoil of .the whole wea on has been received on the shoulder, t e breech block would perform the same unctionas 'the moving member. The velocity of the breech block, which is ythe same as the velocity of the recoiling weapon, drives the block farther to the rear after the weapon has been brought to rest on the shoulder, so that the empty cartridge case can be ejected and the closing spring compressed. If the! unlocking were completed after the weapon has come to rest against the shoulder, the block would possess no backward velocity at the moment 'of unlocking, so that the closing spring would not be compressed. A premature re is impossible; if the locking bolts e are not properly locked, the firing pin cannot be 'urged forward'. By the act o firing the bolts are forced into their position by the firing pin. v

Besides the simplicity of the arrangement., there is the additional advantage that the cartridge case is not in the least shifted by the gas pressure during the unlocking of the breech block. It is known that with weapons in which there is a large gas pressure and cross locking the friction between the lock' ing surfaces is so great that no force is suic ient to unlock the breech'blck at the right time, and that therefore the force available for unlocking is soon used up. In order to avoid this drawback, the inclination of the locking surfaces was limitedto Q0 (the limit of automatic locking) to diminish the work spent in unlocking and in order that the breech block mightbe more easily moved backward. 1n such constructions two drawbacks arise, which are not easily overcome, in the first place the danger that after some hundreds of shots have been ired, the breech block would become a friction block, in which the wear of the locking surfaces would always increase so that the breech block would gradually be unlockedr more quickly. In the second place the cartridge cases would always be slightly shifted and this shifting would gradually increase with the wear of the bolts, so that the cartridge cases after fire would no longer ,it in the cartridge chambers. These drawbacks are entirely obviated by the present'invention. The eiort required can be lessened by the 'proper choice of the .angle f (Fig. 13) without any shifting of the cartridge case.

Since according to the .invention the cartridge cases remain in their chambers until the unlocking is completed and the breech block after the unlocking is suddenly set in motion, it might happen that the cartridge cases might not be extracted by the cartridge extractor, but remain in the barrel. To remedy this drawback the extractor 1" (Figs. l and-2) can be displaced in the axial direction by about a millimeter and is provided with a projection r which engages in a corresponding recess of the fore part a of the breech block. If there is a cartridge in the chamber, the extractor is pushed in about a millimeter, when the breech is being closed, so as to give upward and fasten into the rim of the cartridge case. On the rearward motion of the breech block the extractor is held forward by the cartridge case7 so that the shoulder r1 engages in the corresponding recess of the breech block, so as to prevent -any yielding of the extractor.

I claim as my invention 1. ln an automatic firearm designed to recoil as a whole, a breech-block which is designed to remain in its breech-closing position until such recoil is arrested, a lockingbolt carried by the breech-block, means for normally holding the locking bolt outwardly in engagement with a relatively fixed portion of the rearm, the coperating surfaces of the locking bolt and said relatively fixed A portion of the lirearm being on a plane inclined to the longitudinal axis of, the Weapon sc that the forces acting on -the locking bolt will lexert a turning moment for initiating the unlocking of the breech, and means movable independently of the breech block after the recoil of the firearm for drawing said locking boltinwardiy to complete the un; locking of the bolt. Y

tively fixed part of the firearm,

erating surfacesof the bolt and the firearm 2. In an automatic firearm' designed to recoil. as a whole, a breech-block which is designed to'remain in its breech-closin position until such recoil is arrested, a loc ingbolt having a member pivoted at its rear end and movable laterally at its forwardend, said bolt being designed toy engage a relathe copbeing on a plane inclined to the longitudinal axis of the firearm, and a firing pin movable relatively to the breech block after the recoil of the firearm for withdrawing the locking bolt and unlocking the breech.

3. In an automatic firearm designed to recoil as a Whole, a breech-block which is designed to remain in its breech-closing position until such recoil isarrested, said breechblock being composed ,of two parts, a movable member carried by one of said parts, a-

locking bolt carried by the other'part for normally holding the breech-block to a relatively fixed portion of the firearm, and

, means carried by said movable member for engaging the locking bolt to free the breech- ,coil as a Whole,

the firearm, after the recoil of the latter.

4. In an automatic firearm designed to rea breech-block which is designed to remain in itsbreech closin position until such recoil 1s arrested, said reeehblock being composed of two parts, one of which has an independent relative movement at the completion of the recoil, a firing l pin carried by said part, a locking bolt carried by the other part for normally holding the breech-block to a relatively fixed portion of the firearm, and means carried by the firing pin for engaging .the locking bolt relatively the recoil to free the breech-block from the fixed portion of the firearm after of the latter.

In testimony whereof, I have signed this specification in the presence of two subscribing Witnesses.

`ARIS D. cHRoNis.

lvitnesses l CONSTANTINE M. CORAFA,

DEURETRios BoYzEAL. 

